Method of separating the galvanoplastic deposits from metal matrices.



TmTTnp STATES PATENT oTTron.

EUGEN ALBERT, OF MUNICH, GERMANY, ASSIGNOR TO FERDINAND WVESEL, OF NEWYORK, N. Y.

METHOD OF SEPARATING THE GALVANOPLASTIC DEPOSITS FROM METAL MATRICES.

Specification of Letters Patent.

Patented Dec. 26, 1905 Application filed June 21,1905. Serial No.266,232.

To all w71/0771/ it nm l concern:

Be it known that I, EUGEN ALBERT, a subject of the King of Bavaria,residing at 55 Schabingerlandstrasse, Munich, in the Kingdom of Bavaria,Germany, have invented certain new and useful Improvements in Methods ofSeparating Galvanoplastic Deposits from Metal Matrices, of which thefollowing is a specification.

The ordinary way of detaching galvanoplastic deposits from metalmatrices is to coat the surface of the matrix with some substance suchas silver or graphite before the deposit is made, whereby the depositmay be the more easily separated from the matrix after theelectrodeposition has taken place. While this method of separating thedeposits from the matrices is satisfactory in some cases as withphotogravures, for instance-good results are not obtained when thismethod is applied in the electrotyping art. Owing to the form of thetype or printing elements, the deposits cannot be separated from thematrices, notwithstanding the application of a coating between the same,without causing more or less deformation of the electros. Another methodof separating deposits from the matrix-base is to melt down the base,whereby it is destroyed and cannot be used over again.

The object of this invention is to provide a convenient method ofremoving galvanoplastic deposits from metal matrices in accordance withwhich the separating takes place so easily that the deposit or electrois removed in perfect condition,while at the same time the metal matrixor base is uninjured and may therefore be used over and over again.

In accordance with the invention the matrix with the deposit thereon tobe separated therefrom is suddenly heated within certain deiinite limitsof temperature, which causes the deposit to spring ofi from the matrix.This sudden heating can best be accomplished by providing a suitablebath, preferably a metallic bath, on account of the comparatively hightemperature required, into which the l matrix with the deposit thereonis floated or immersed. If desired, however, the liquid from the bathmay be poured upon the deposit and the matrix to effect the separation.

The temperatures of the bath should be chosen with particular regard tothree considerations. The first consideration is that the temperature ofthe bath should not be too high, so as to affect the elasticity orhardness of the deposit, and thereby harm or ruin its printingqualities. In the next place the temperature should not be high enoughto fuse the matrix, and thereby destroy it, so that it cannot be usedagain. Finally, the temperature of the bath should be sufiiciently abovethe fusing-point of the bath so that when the bath is cooled by theinsertion of the matrices and deposits the bath should not solidify.

In carrying out the invention it is therefore preferable to provide ametallic bath with a considerably lower fusing-point than that of themetal matrix and to heat this bath almost up to the fusing-point of themetal matrix. In this way when the matrix with the deposit comes incontact with the bath it will be suddenly heated and the deposit Will becaused to spring off from the matrix, whereby it may be convenientlyremoved therefrom and the matrix used over again.

In the electrotyping art where copper deposits are formed and where alead matrix is employed the bath may comprise the ordinary backing metalemployed in electrotyping which fuses at 220 Centigrade, or an alloy offifty-seven parts of lead and thirty-three parts of tin may form thebath, such alloy having a melting-point of 150 Centigrade.

In many cases the fusing-point of the backing metal will be suflicientto eifect the separation, and accordingly the separation may be effectedsimultaneously with the casting of the backing metal upon the deposit.The tinning of the deposit, which is done in order to secure the backingto the matrix, may be effected by placing the leaflets or foils of tinupon the deposit after its deoxidation, and

thus the deposit may be tinned over simultaneously with the detaching ofthe same from method consists in heating the bath to a point the metalmatrix. lower than the fusing-point of the matrix and I claim as myinvention l floating the deposit and matrix thereon. 5

ces by employing a metallic bath, which 5 1. The herein-described methodof separat- In witness whereof I have hereunto signed ing galvanoplasticdeposits from metal matrimy name in the presence of two subscribing ces,which method comprises the application witnesses. to the deposit andmatrix of a metallic loath in EUGEN ALBERT. order to suddenly heat thedeposit and matrix. Witnesses:

IO 2. The herein-described method of separat- HENRY HASPER,

ing galvanoplastic deposits from metal matri- VVOLDEMAR HAUPT.

